Air pump



Patented Apr. l, 1924.

iTEn STATES JOHN P. QUINN, 0F NEW YORK, N. Y.

AIR PUMP.

Application filed May 10, 1923. Serial No. 638,086.

To all lwhom t may concern.'

Be it known that I, JOHN P. QUINN, a citizen of the United States7 and a resident of the city of New York, borough of Bronx, in the county oi Bronx and State of New York, have invented a. new and Improved Air Pump, of which the following is a full, clear, and exact descrip-tion.

My invention relates to a pump, more par-A ticularly an air pump, such as is utilized for the inflation ot pneumatic tires fo-r'motor vehicles.

It is a well known and appreciated fact in connection with the type or pump specified, that a number of di'diculties have been experienced. Thus primarily it has been found, in pumps which have been in use for a certain length of time, that a certain amount of leakage will exist at the point of connection between the cylinder and base thereof.

1n this connection it is to be noted 'further that the construction of the joint at this point has always been more or less of a relatively tedious nature, thus increasing the expense of the finished article, and it is also understood that a further ditiiculty hasbeen found to exist in that the valve mechanism has notoperated properly and the operator has not received the ultimate compression value of the full stroke of the piston.

lith these defects in mind, my present invention aims to provide a pump, in which a joint will be formed between the base and the cylinder in such a manner as to virtually preclude any possibility of a leak existing at this point, regardless of the usage to which the pump may be subjected.

A further object of this invention is the construction of a device of the character stated, in which the diiiiculties incident to the valve mechanism will be eliminated and in which the operator will receive the full compression value of the stroke of the piston.

the provision of a pump which may be placed on the market at a nominal figure, and still further objects will appear in the annexed specification taken in connection with the drawing, which latter presents one practical embodiment of the same and in which- Figure 1 is a side elevation of a pump em bodying my improved construct-ion.

Still another object of this invention is plunger 11 extends, a handle 12 being asso ciated with the plunger i'or the purpose oi reciprocating the same. Further, a base 13 'of any desired type is provided with which the cylinder r is associated in a manner hereinafter described, and 'a discharge' tube 1a is connected with the base, as in the standard types of pumps. Contrary to the conventional construction, however, it will be noted that the plunger 11 is formed with a bore 15 which extends throughout its entire length, an opening 16 being provided adjacent the upper end of this bore through which communication may be had with the outer atmosphere. Further, a, piston is aiiixed to the lower end of the plunger 11 and this piston preferably includes a. body portion 17, packing elements 18 and clamping nuts 19.

Attention is now invited to Figures 2 and 5 and it will be seen in these figures that a valve cage 20 is screwed to the lower end of the plunger 11 and that a check valve 21 cooperates with the valve seat 22 formed at the lower end of the plunger. .also7 with a view of avoiding any diiiculty incident to back pressure, a relief opening 23 is formed in the upper end ot the cylinder 10 and thus it will be understood that upon an operator withdrawing the plunger 11 that the air will be free to iiow from within the cylinder 10, through the relief opening' 23, the same being also true when the plunger is projected. Further, whenl the plunger rod is withdrawn, air will flow through the inlet opening 16 and bore 15 of the plunger rod 11, and Aincident to the fact that the valve 21 is unsealed this air will be free to pass into ythe compression chamber existent between the piston and the lower end of the cylinder. Immediately upon the direction of the motion of the plunger being reversed, the valve 21 will be seated and the air within the compression chamber will now be compressed and be discharged through the outlet opening 24C in the base 13 and thence into the discharge tubing lll in return of this air being precluded, incident to the check valve (not shown) associa-ted with the tube lli.- this lat-ter feature being conventional construction.

Now, with a view of providing means which will overcome the heretofore existing difficulty at the point of connection of the cylinder with the base, it will be noted that this latt r element provides a collar 25 which is internally screw threaded and of a diameter corresponding tov that of the cylinder l0. A hollow stud 25 formed with a perforate end 26 is arranged within the collar 25 and it is to be noted that the side walls 2'? of the stud taper throughout their entire length, so that a wet ge is presented, which wedge preferably presents teeth 28 in its outer face.

The lower end of the cylinder is formed with screwA threads corresponding with threads of the collar 25 and these elements may now be associated with each other, and after this has been accomplished a split supplemental collar 29 is ii'itroduced into the cylinder l() and forced to the position shown in Figure 2, it being noted that the side Walls of this collar are formed so as to taper to an extent corresponding to the tapering of the side walls of the stud, and further it will be seen that the inner faces of the same are also formed with ratchet teeth corresponding to the ratchet teeth of the memloer 25.

In this connection it will, of course, be appreciated that the introduction of the split collar takes place while the plunger rod and piston are removed from the cylinder, and it will thus be seen that neon the collar being forced home that a wedging action will be effected which will serve to pinch the cylinder l0 between the split collar and the collar 25 of the base 13, thus obviously preventing any leakage at this point and providing a connection which will withstand the hardest usage.

It is also to be noted that the supplemental collar 29 may conveniently be formed with projections 30 as in Figure 3, and these projections extend into a grip within correspondingrecesses in the 'cylinder 10, thus preventing any movement of these parts with respect to each other, a. movement on the part of the supplemental colla-r with respect to the stud being in turn prevented incident to the teeth 2S, and finally the stud 25 being retained in position by the cylinder, which is thus providing an inten locking structure.

Inithe foregoing it will he understood that all the objects set forth in the preamble to this specification are accomplished and it will further be appreciated that numerous improvements of structure might easily be allowed without in the least departing from the scope of my claims which are-- l. In a pump, the combination with a base and a cylinder, said base having a screw-threaded recess therein receiving the lower end of the cylinder, a plug` centrally located in the cylinder at its lower end, and an expansible ring positioned around the plug and engaging the inner face of the cylinder.

2. In a pump, the combination with a base and a cylinder, said base having a screw-threaded recess therein receiff'ing the lower end of the cylinder, a plug centrally located in the cylinder at its lower end, and an eirpansible ring positioned around the plugand engaging the inner face of the cylinder, said plug and internal bore of the ring being wedge-shaped in longitudinal section. y

3. In a pump, the combination with a base and a cylinder, said base having a screw-threaded recess therein receiving the lower end of the cylinder, a plug centrally located in the cylinder at its lower end, and an expansiblc ring positioned around the plug and engaging the inner face of the cylinder, said plug and internal bore of the ring being wedge-shaped in longitudinal section, said plug having annular serrations engaging the inner face of the ring.

la In a pump, the combination with a base and a cylinder, said base having a screw-threaded recess therein receiving the lower end of the cylinder, a plug Centrally located in the cylinder at its lower end, and an eXpa-nsible ring positioned around the plug and engaging the inner face of the cylinder, said plug having a base portion receiving thereon the lower end of the cylinder.

JUIAIN P. QUINN. 

